基于碳纳米纤维的非贵金属电催化剂的理性合成和性能研究

To commercialize the new energy devices, such as fuel cell and metal-air battery, it is highly important to develop the low-cost and high-performance non-precious metal catalysts (NPMCs) to replace the expensive noble metal electrocatalysts. Transition metal/nitrogen-doped carbon materials (Me/N/C) are considered as one type of the most promising NPMCs, due to their low cost, abundant reserves and excellent performance. However, the performances of Me/N/C electrocatalysts are still worse than that of noble metal electrocatalysts. Developing rational and controllable synthetic techniques and understanding the active sites of Me/N/C electrocatalysts play a critical role in the enhancement of the performance for these catalysts. In this project, we will rationally synthesize a series of Me/N/C NPMCs with different chemical constituents and structures from carbonaceous nanofibers based on different electrochemical reactions. The performance of these catalysts in different electrochemical reactions will also be carefully investigated. Besides, the main active sites and their structures will identified by the performance of different electrocatalysts as well as advanced characterization techniques. The goals of this project are to realize the rational synthesis of Me/N/C NPMCs, identification of the active sites and enhancement of the performance. Moreover, the obtained low-cost and high-performance Me/N/C NPMCs are expected to be used in the new energy devices, such as fuel cell and metal-air battery.

寻求廉价、高效的非贵金属电催化剂，以替代昂贵的贵金属电催化剂，是大规模商业化燃料电池、金属空气电池等新型能源器件的最大挑战之一。过渡金属/氮掺杂碳材料（Me/N/C）具有低廉的价格、丰富的储量、优异的性能，被认为是最有前途的一类非贵金属电催化剂。然而，Me/N/C类催化剂的性能仍落后于贵金属催化剂。发展可控的合成方法和深入理解Me/N/C类催化剂的活性位点是提升这类催化剂性能的关键。鉴于此，本项目拟使用碳纳米纤维为碳载体，根据不同催化反应的要求，合理制备一系列组分、结构可控的Me/N/C类非贵金属电催化剂，并研究这系列催化剂在几种电催化反应中的性能。在比较系列催化剂性能的基础上，运用先进的表征技术，探究所合成催化剂的主要活性位点。以实现Me/N/C非贵金属电催化剂的可控合成、活性位点的理解和性能优化，并探索Me/N/C类催化剂应用于燃料电池、金属空气电池等新型能源器件的可行性。

伴随着工业化和现代化进程的加速，人类社会正面临着能源短缺和严重的环境污染等问题，本项目以廉价、高效的非贵金属电催化剂替代昂贵的贵金属电催化剂的理念为导向，主要研究了以下几个方面：研制了基于价廉的细菌纤维素的一类新型纳米纤维固体酸催化剂材料，通过不完全碳化和磺化天然纳米纤维素，并在一系列重要的酸催化反应中性能均优于目前通用的固体酸催化剂；综述了新兴碳纳米纤维气凝胶的化学合成与生物合成方法，这些方法都适用于大规模碳纳米纤维气凝胶的生产；提出了一种过渡金属盐辅助热解有机小分子来制备碳纳米材料的方法被提出，发现至少15种有机小分子和9种过渡金属盐可以作为碳前驱物和催化剂来制备相应的碳基纳米材料，同时多种硬模板可以用在该方法中来提高所得材料的比表面积和多孔性；发展了一种新型的双功能电催化剂对OER和HER都表现出优异的催化活性和耐久性。